The present invention relates to generally to network systems using redundant or standby router devices working together in a redundancy group to provide a virtual router service. More particularly, it relates to mechanisms for virtual routers within a redundancy router service that also implements virtual ports or sub interfaces on the router devices.
Virtual router protocols such as HSRP (Hot Standby Router Protocol) and VRRP (Virtual Router Redundancy Protocol) are used to provide a redundant router service on a subnet. Typically, two or more routers participate in the election of a router that is responsible for forwarding traffic sent to the virtual router. If that router (or interface) fails then another member of the group will take its place and continue to forward traffic sent to the virtual router.
Increasingly, many hundreds of virtual ports or sub-interfaces are being configured on the same physical interface of a router, with each sub-interface having its own virtual router group. Each virtual port is typically configured to communicate with its peers in the same virtual router group. The negotiation and maintenance of multiple virtual routers each having multiple virtual ports can have a detrimental impact on network traffic and CPU utilization.
In view of the above, there is a need for mechanisms for managing redundant router groups where each router can have multiple virtual ports or sub-interfaces.